DNA inoculations with HIV-1 recombinant genomes that express cytokine genes enhance HIV-1 specific immune responses

Vaccination with HIV-1 DNA sequences induce both humoral and cellular immun e responses in experimental animals. However, these responses are relativel y weak and are often only transient in their nature. In order to enhance th e level of HIV-1 specific immunity, we have engineered HIV-1 DNA constructs which contained various cytokine genes such as interleukin-2 (IL-2), granu locyte-macrophage colony stimulating factor (GM-CSF) and interferon-gamma ( IFN-gamma) gene. These constructs have deleted the tat and nef genes of HIV -1 to eliminate their immunosuppressive effects. Immunizations with these r ecombinant constructs elicited moderate proliferative T cell responses but poor antibody responses in rats. However, inoculations of HIV-I DNA that co ntained the GM-CSF or the IL-2 gene significantly enhanced humoral and prol iferative T cell responses, respectively. Thus, recombinant HIV-1 genomes s uch as those described here may increase the efficacy of DNA vaccination. ( C) 1999 Elsevier Science Ltd. All rights reserved.